US2443332A

US2443332A - Seal

Info

Publication number: US2443332A
Application number: US531056A
Authority: US
Inventors: Otto M Summers
Original assignee: HPM Development Corp
Current assignee: HPM Development Corp
Priority date: 1944-04-14
Filing date: 1944-04-14
Publication date: 1948-06-15
Anticipated expiration: 1965-06-15

Description

June 1948? I M. SUMMERS SEAL Filed April, 14, 1944 4 Sheets-Sheet 1' E INVENTOR 0770 H. SUMMERS Arronuzvs June 1948- o. M. SUMMERS SEAL 4 Sheets-Sheet '2 Filed April 14, 1944 INVENTOR OTTO M. 5UMMER$ ATTORNEYS June 15, 1948. SUMMERS 2,443,332

SEAL 7 Filed April 14, 1944 4 Shasta-Sheet 3 V///////////// //%&\

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' ENTOR or'ro M. supm ms BY ad... 44..

A'ITORNEYS O. M. SUMMERS June 15, 1948.

SEAL

4 Sheets-Sheet 4 Filed April 14, 1944 INVENTOR o'r'ro M SOMMEIB,

BY mxm ATTORNEYS Patented June .15, 1948 l I UNITED STATES PATENT OFFICE SEAL Otto, M. Summers, Mount Gilead, Ohio, assignor to H-P-M Development Corporation, Wilmington, Del., a corporation of Delaware Application April 14, 1844, Serial No. 531,056

2 Claims. (Cl. 286-17) I l 2 This invention relates to seal structures that a film of lubricating oil between the ramsurface are adapted to seal upon a moving member that and the seal, the oil flowing past the sea] surface operates through a wall of a chamber containing being continuously returned to the reservoir fluid under pressure to prevent leakage of the the hydraulic circuit. fluid from the chamber. More particularly, the 5 Still another object of the invention is to proinvention relates to a seal structure adapted to vide a seal for a ram of a hydraulic press wherein be used around the ram of a hydraulic press to the sealinember is constructed and arranged in a seal the ram at its point of exit from the ram manner that leakage of a predetermined quantity cylinder and thereby prevent leakage of hydraulic is provided past the sealing surfaces to permit fluid around the ram. I lo lubrication thereof, which fluid leakage is re- Acccrding to the conventional practice in the turned to the reservoir of the hydraulic system,

' manufacture of hydraulic presses, it has been, and wherein the seal structure is adapted to wipe and is, the conventional practice to provide 'a. the surface of the rain clean before it enters the seal member around the ram that is sufficiently seal structure, thereby preventing dirt and grit tight to prevent any and all leakage of hydraulic from entering the seal structure which would fiuid from the rain cylinder. There is a definite tend to grind or wear the surface of the ram and attempt to run the ram dry, because any leakage cut the seal packing material.

of hydraulic fluid around the ram of the hydraulic Still another object of the invention is to propress causes the oil to run over the press and in vide a seal structure for a ram of a hydraulic general produce a very disagreeable workingconpress that is constructed and arranged to permit dition. It is not unconventional for pressures as a normal or predetermined leakage past the seal high as 2,500 lbs. per square inch to be used in the for normal lubrication of the ram surface when main cylinder areas of the ram for operating the operating in the seal structure and which is also same. Therefore, to resist leakage of fluid around constructed and arranged to return all leakage the rain it has required the development of special 26 fluid to the reservoir of the hydraulic system inseal structures that are in intimate contact with eluding any abnormal fluid leakage past the seal the surface of the ram with suflicient pressure structure that should occur due to abnormal'conapplied thereupon to prevent the high pressure in ditlons.

the ram cylinder areas from leaking past the seal Stillanother object of the invention is to promember. vide a seal structure for the ram of a hydraulic The result of prior ram seal structures has press wherein the ram can operate within the seal therefore resulted in the operation of a substanstructure under a condition wherein the seal tially dry ram, having regard to the working surstructure is flooded with oil to provide lubrication faces between the 'ram and the seal member. of the ram while therein and yet that part of the Such dry working surfaces are not eflicient in ram outside the seal structure will have a rela-= operation because considerable friction is develtively dry circuit to thereby prevent oil from the oped between the ram and the seal surfaces which hydraulic surface from running over the press prevents freedom of movement of the ram, and body'and causing unsatisfactory working condiin conventional rapid traverse presses the fric-- tions.

tion between the seal and the ram has in many 40 Further objections and advantages will become instances been sufllcient to prevent the mm r apparent from the drawings and the following falling freely during the rapid traverse movedescription, merit. This is noticeably true in small presses. drawings;

Also the operation of a ram having dry Fig. l is a cross-sectional view of a hydraulic irg oll'er a sfeal memllzer that isialsoflilll press illustrated somewhat diagrammatically to 2,2, 3 ig zzi g g z g g g g show the application of the seal structure of this invention to the same. the surface of the seal and as final result leak- Fig. 2 is an enlarged cross-sectional view of the age of hydraulic fluid'from the press increases at an ever-increasing rate as the operation of the Seal structure of this invention illustrating the press continua manner in which fluid flowing through the seal It is therefore an object of this invention to structure is removed therefrom for return to h provide a seal structure for a ram of a hydraulic reservqir 0f the hydraulic Systempress that is constructed and arranged in a man- 3 s an enla d p p t vi w f the ner that hydraulic fluid from the hydraulic cirv wiper ring that forms a part ofthe seal structure cult can continuously flow past the seal to provide of this invention.

Fig. 4 is a cross-sectional view of the seal structure of this invention illustrating the manner in which the wiper ring is retained in postion.

Fig. 5 is a cross-sectional view of a slightly modified form of the seal structure of this invention.

Fig. 6 is a. cross-sectional view of a further slightly modified form of the seal structure.

Fig. 7 is a cross-sectional view illustrating the manner in which the ends of the wiper ring are secured together.

Fi 8 is a plan view of the wiper ring illus-' trated in Fig. 7 showing the fastening means therein..

Fig. 9 is a cross-sectional view of the wiper ring as illustrated in Fig. 5 showing a "modified arrangement thereof.

Figure 10 is a cross-sectional view of an arrangement of the wiper ring constructed with a separate seal member.

Figure 11 is a cross-sectional view illustrating the unconfined form of the wiper ring illustrated in Figure 10.

The seal structure of this invention is applicable to the ram of a hydraulic press as diagrammatically illustrated in Fig. 1. As illustrated,

the hydraulic press consists of a ram l having a piston-head II that reciprocates within a cylinder l2 that has the cylinder bore I3 to receive the piston-head I I.

A seal member I is disposed between the ram i0 and a recess l4 provided in the lower end of the cylinder bore l3. The seal member i5 therefore seals or closes the space l6 provided between the ram Ill and the cylinder bore l3 which receives fluid under pressure through the conduit H. The fluid under pressure in the space l6 acts upon the lower surface of the piston-head II for producing a retraction movement of the ram ID. The upper chamber ll! of the cylinder I2 is supplied with fluid under pressure through a conduit IS. The conduits I! and I! are connected toa suitable source of fluid under pressure such as a reversible variable delivery pump that sup plies fluid to either of the conduits l1 and IS in response to controls that are well known in the art. a

The seal members l5 used around the press ram ill have heretofore been constructed and arranged to prevent any leakage from the chamber i6 along the wall of the ram Ill in an attempt to keep the lower portion of the ram dry. The seal structure of this invention, however, permits a controlled flow of hydraulic fluid, such as oil, past the seal member along the wall of the ram ID to provide for lubrication of the same, and conducts the fluid away from the ram so that the lower portion thereof can still operate as a dry ram but with suitable lubrication provided over the area that is in contact with the seal member ii.

The structure of the seal member I! is more specifically disclosed in Figs. 2, 3 and 4. As disclosed in these figures the ram l0 operates within the cylinder I2 and the seal member I5 is disposed within the recess I 4 provided in the lower portion of the cylinder bore l3.

The seal structure consists of an upper retaining ring 20 that is made from metal and is disposed between the ram l0 and the wall of the recess H. The retaining ring 20 is held in position by the inter-engaging taper surfaces 2| provided on the ram Ill and the wall of the recess ll.

A plurality of packing rings 22 are positioned in the recess l4 around the ram 10. ,These packing members 22 are known in the art as V-packing members. The

straight sidewalls

23 and 24 of the packing members 22 engage the surface of the ram I0 and the surface of the recess it to thereby seal against the same when pressure is applied upon the packing members 22. The packing members 22 are conventionally made from linear packing material that is cut to the desired length to circumferentially enclose the ram iii, the ends of the packing members 22 being suitably tapered or scarfed to provide an efiective sealing across the ends of the packing members at their juncture.

Each of the packing members 22 is constructed with a substantially U-shaped bottom section 25 that is adapted to engage the upper V-shaped fiat surface 26 of the packing member that is disposed beneath the same. The association of the vshaped bottom sections of the packing members with the V-shaped top sections thereof therefore provides small space areas 21 between the edges of the packing members and along the center portions thereof.

A gland ring 28 is inserted in the space between the wall of the recess l4 and the wall of the ram iii to engage the lowermost packing member 22.

This gland ring 28 is retained in the position illustrated in Figs. 2 and 4 by means of a retaining ring .29.- The retaining ring 29 is suitably secured to the wall ll of the cylinder by means of bolts, studs or nuts 30. These bolts are tightened sumciently upon the retaining ring 29 to cause the gland ring 28 to apply pressure upon the packing members 22, to compress the same, to place the

edges

23 and 24 of the packing members 22 in re1atively tight frictional engagement with the wall of the recess 14 and the wall of the ram Ill. The degree of compression of the packing members 22 will control the quantity of hydraulic fluid that is permitted to flow between the edges of the packing members 22 and the walls that they engage.

In the usual and conventional construction of seal members, the gland ring 28 is moved upwardly until the packing members 22 are comthereupon causes sufficient frictional engagement thereof with the wall of the recess i4 and the wall of the ram l0 that hydraulic fluid from the chamber I6 is prevented from leaking through the packing members. relatively high compression of the packing members 22 and produces high frictional engagement between the packing members 22 and the wall of the ram III which wipes the wall of the ram I0 dry as it passes across the surface of the packing members 22. The dry working surface of the ram I0 is therefore scored as a result of its movement across the surface of the packing members 22. Any oil leaking past the packing members 22 would, in a conventional hydraulic press, run down the surface of the ram and flow over the dies. If the leakage is not stopped promptly, by the replacement of the packing members, it continuously becomes worse as long as the press is operated under these conditions.

In the seal structure of this invention there is provided a wiper ring 3| that is provided for collecting and directing a controlled flow of fluid past the seal members 22 so that the controlled leakage can be returned to a supply reservoir of the hydraulic system through the conduit 32. The wiper ring 3| is shown in more detail in Fig. 3 that illustrates a cross-sectional view of the wiper ring when in relaxed condition.

The wiper ring 3! is provided with a plurality of This, therefore, requires alongitudinally extending ridge portions 33 that are substantially V-shaped in cross-section. It will that the apex ofeach of the V-shaped segments 33 extends toward the axial center of the general arcuate contour of the wiper ring 3|. The plurality of V-shaped segments 33, therefore, provides a plurality of longitudinally extending recess areas 34 that provide chambers to receive hydraulic fluid when the wiper ring cooperates with the ram in a manner to be hereinafter described.

The wiper ring 3| has the V-shaped segments 33 disposed on one side of the longitudinal center thereof positioned with the apex of each of the longitudinally extending segments positioned toward the outer edge of the wiper ring 3|. Thus, the segments 33 are positioned in an opposite direction to the segments 33a so that the segments 33 will produce a squeegee operation or function upon the surface of the ram l3 when it moves in one direction and the segments 33a will produce a similar squeegee function upon the surface of the ram l3 when it moves in an opposite direction. The wiper ring 3| is provided with a longitudinally extending ledge portion 35 that cooperates with the body 36 thereof to form a recess 31 that is provided for the purpose of cooperating .with the retaining ring 29 to hold the wiper ring 3| in position in the manner illustrated in Fig. 4.

The wiper ring is preferably constructed of one of the synthetic rubber-like materials, such as Duprene, neoprene, Buna S or any of the other synthetic rubber-likematerials that are resistant to oil.

The wiper ring 3| can be produced as an extru'ded article of manufacture in any desired length, and can be cut to-a length desired that illustrated in Fig. 4 the general arcuate contour of the ring, as illustrated in Fig. 3 is straightened out into the flat contour illustrated in Fig. 4. The flexing, or straightening, of the contour of the wiper ring 3| produces a pressure upon the surface of the ram ill to retain the wiper ring 3| in frictional engagement with the surface of the ram l3.

The

recesses

39 and 40 provide a chamber that receives the wiper ring 3| that is substantially larger, in length. than the wiper ring 3|. The space 4| in the upper portion of the chamber forms an annular space aroundthe ram Ill between the wiper ring 3| and the gland ring 23 into which the hydraulic fluid that flows, or leaks, past the seal members 22 enters. 'A similar space 42 is provided beneath the wiper ring 3|,

and communicates with the atmosphere directly supplies fluid under pressure to the cylinder 2 of the press. It'will therefore be seen that the annular space 4| is a space of relatively low pressure, if any, because the conduit 32 is connected with the exhaust side of the hydraulic system, which is open-to the atmosphere.

The gland ring 23 is provided with an annular recess 41 that receives a circular ring 43 of run: ber-like material. This ring of rubber-iikemate rial, which can be one of the synthetics previously mentioned, has the ends thereof in abutting relationship so that when slight pressure is "applied upon opposite sides of the ring to slightly deform the same, the engagement of the ring with the recess 41 and the wall of the recess l4 will prevent fluid passing downwardly along the wall surface of the recess l4. A passageway 43 is provided between the recess 41 that receives the seal member 43 and the lower surface of the lowermost seal member 22. A second passage 53 is provided between the lower portion of the lowermost seal member 22 and the surface between the ram l3 and the gland ring 23. The

passages

49 and 50 therefore connect the recess.

41 and the lower portion of the lowermost seal member 22 with the low pressure chamber or space 4| to permit relief ofpressure from the recess 41 which would cause leakage of fluid pastthe seal member if this pressure should become excessively high, which would normally be the case if liquid was trapped in this chamher.

The retaining ring 23 has an annular recess 5| that receives the ledge portion 35 of the seal ring 3|, and the gland ring 23 has an annular recess 52 that cooperates to receive a part of the ledge portion 35 to thereby retain the wiper ring 3| in position as illustrated in Fig. 4. v

In operation, .the elements of the seal structure are assembled as illustrated in Figs. 2 and sufliciently to prevent .all leakage of fluid between the ram ill and the packing members 22, as has previously been done. Instead, the packing members 22 are compressed to a point at which a. certain amount of leakage will occur between the surface of the ram l0 and the packing members 22. This'leakage, or intentional flow of hydraulic fluid, between the ram ill and the packing members 22 will permit a continuous flow of hydraulic fluid past the seal members 22 to thereby maintain a film of oil between the surface of the ram l3- and the packing members 22 whenever the pressure in the hydraulic system is high. The surface of the ram will therefore be lubricated when it reciprocates through the packing members 22. In addition the spaces 21 are charged with fluid which provide lubrication for the surface 'of the ram when the pressure in the chamber I3 is low. therefore giving the ram surface continuous lubrication regardless of whether high or lowpressure is in the cham-- ber l5.

The hydraulicfluid that flows past the seal members 22 enters the chamber 4|. However,

How-- since this chamber 4| is connected to the low pressure side of the hydraulic system, such as the reservoir, there can be no pressure in the chamber 4 I. The fluid which enters the chamber 4| will pass through the fitting l5 and the passage 46 to the conduit 32, and thence to the reservoir, or the low pressure side of the chamber. In any event, the fluid which enters the chamber M will not pass by the wiper ring 3| because the wiper ring frictionally engages the surface of the ram l0, and the ridges 33a on the wiper ring 3| squeegee fluid from the surface of the ram I0. Therefore when the ram l passes by the wiper ring 3! all surplus oil is removed therefrom and passed into the chamber H. The portion of the ram that moves outwardly from the retaining-ring 30 will therefore be relatively dry.

The frictional engagement of the wiper ring 3i upon the surface of the ram 10 is required only to cause movement of the fluid from the chamber M to the reservoir connected to the conduit 32.

The lower segments 33 of the wiper ring 3! produce a squeegee action upon the surface of the ram Hi to wipe the surface free of foreign particles when the ram moves in an upward direction as viewed in Figs. 1 and 2. This, therefore, prevents foreign particles from entering the space occupied by the packing members 22 so that the life of the packing members is greatly increased.

In order to permit the installation of the wiper ring of this invention upon presses that are already "installed in the field, and to permit the functioning of the seal members in the presses installed in the field in accordance with the principles disclosed in this invention, certain modifications of the structure of'the retaining members for the wiper ring must be produced to permit the use of existing parts in the presses that are in the field. Such a modified arrangement of structure is disclosed in Fig. wherein the retaining ring for the seal members has been reoperated to permit installation of the wiper ring of this invention and thereby permit the conventional packing member to function in accordance with the principles of the invention. It is, of course, understood that a new retaining ring can be provided if desired.

In the arrangement listed in Fig. 5 the upper gland ring 60 is disposed between the ram Ilia and the wall of the recess Ma provided in the lower end of the cylinder l2a in the same manner as heretofore described with regard to Fig. 2. At least, the upper gland ring 60 need not be changed from the existing construction of gland ring that is provided in the seal structures that are present in the presses now in use. The packing members 22a are identical with the packing members heretofore described with regard to Fig. 2 and function in the same manner.

Normally, the retaining ring 6| isprovided same function as the seal member 48. The retaining ring 66 is also provided with a recess 66 to receive the wiper ring 3la that is in all respects similar to the construction of the wiper ring 3| previously described with regard to Fig. 2. The wiper ring 3i (1 is provided with an extending ledge portion 61 that is received in an annular recess 68 provided in the retaining ring 6|, a ring member 69 being secured to the retaining ring 8| to hold the wiper ring 3la in position as illustrated in Fig. 5.

The space, or chamber, 10 provided above the wiper ring am, similar to the space Ii previously described-with regard to Fig. 4, is connected to a, passage II that in turn connects with a conduit 32a. The conduit 32a connects with a supply reservoir, or low pressure side of the hydraulic system, in the same manner as conduit 32 previously described.

The operation of the seal structure illustrated in Fig. 5 is the same as the operation of the seal structure previously described. Hydraulic fluid that moves along the wall surface of the ram Illa will be conducted from the chamber 10 into the passage ii for return to a reservoir, or low pressure side of the hydraulic system, by means of the conduit 32a. During the upstroke of the ram Ilia the wiper ring 3ia will remove foreign particles from the surface of the ram to prevent them from entering the chamber in which the seal members 22a are located.

If it is desired to increase the degree of frictional surface engagement between the wiper ring 3Ia, or the wiper ring 3!, such increase in frictional surface engagement can be obtained by placing a coiled spring member 15 around the body of the wiper ring as illustrated in Fig. 9. This increase in frictional engagement will prevent any seepage of oil between the wiper ring 3| and the surface of the ram l0 so that the lower portion thereof will work substantially free of oil.

If the increase in frictional engagement between the wiper ring and the ram is desired adjacent the lower portion of the wiper ring, the spring member 15 may be positioned around the lower portion of the body of the wiper ring as illustrated in Fig. 9. This will increase the effectiveness of the wiping action of the wiper ring upon the surface of the ram to remove foreign particles from it during the upward stroke of the ram.

If, however, the increase in frictional engagement between the wiper ring 3| and the surface of the ram I0 is desired for the purpose of preventing absolutely any seepage of oil past the wiper ring, the spring member can be positioned around the body of the wiper ring adjacent the upper edge thereof as illustrated by the spring member (5a shown in Fig. 6. The action of the spring member in this latter instance may be required when the oil that flows into the chamber I0 is required to be raised to a relatively high level, such as in those instances wherein the surge tank or reservoir is located on top of the head of the press. a

In Figure 10, the ram lob operates in the cylinder I221, the ram 10b being the ram of the hydraulic press as heretofore described. An upper gland ring 20b is disposed between the ram lb and the cylinder [2b against which the packing rings 22b are supported. The packing rings 22b are constructed similarly to the packing rings 22 heretofore described with regard to Figure 2.

The lower gland ring for compressing the packing rings 22 consists of a gland ring portion M0 that is an integral part with the supporting ring Ilii that is secured to the cylinder l2b by the bolts ill! extending through the supporting ring llll into threaded engagement with the cylinder lib. The gland ring portion I has a recess I" that receives a packing member I of rubber-like material. The packing member I is preferably circular in cross-section, when in an uncompressed condition, and is of linear material so that any desired length thereof can be cut to encircle the ram and be positioned in the groove I03 with the ends thereof in abutting relationship.

A passage I08 extends between the surface of the ram lb and the cylinder i217 to prevent development of high pressures above the packing member I03.

The retaining ring III has a recess I06 that receives a wiper ring I" retained therein by means of the retaining ring l2l which when positioned in the recess ili, engages the outer periphery of the ram llb.

The wiper ring IN is more specifically shown in Figure 11 and consists of a body portion I08 that is provided with an arcu-ate concave surface I09 that engages the surface of the ram and applies pressure thereon to seal against the min. A tongue illl is carried by the body I08 of the wiper ring and is placed in a recess l I i in the ring llil to locate the wiper ring in position, and retain the same on the ring "H. A plurality of longitudinally extending ridge portions 2 are formed in the face of the wiper ring to wipe the surface of the ram during its upward stroke, as illustrated in Figure 10. While the wiper ring III! has been specifically mentioned as a ring member, yet it is to be understood that it is made from linear material that is cut to the desired length in the same manner as heretofore described with regard to the ring illustrated in Figure 3.

A recess H is provided in the ring llil above the upper edge of the wiper ring I01 that receives a seal member II. The seal member H6 is preferably circular in cross-section, when not under compression, and is formed of linear material that is cut to the desired length to encircle the ram lob so that the ends of the member 6 abut one another.

An annular chamber 1 is formed between the ram llib and the recess 5 in which the seal member H6 resides so that any pressure in the chamber III will tend'to compress the resilient rubber-like seal member iii and force the same against the surface of the ram lob in directproportion to the pressure existing in the chamber III.

In accordance with the operation of the seal structure heretofore mentioned with regard to the other figures of the application, the seal members 22b are supplied with oil moving between the ram lob and the seal members 221:. This oil collects in the chamber Ill and is directed to a reservoir chamber through the passage IIS and the connecting passage I20.

The wiper ring ill and seal member H6 provide means whereby the ram below the wiper ring I01 is retained free of oil, and grit is prevented from entering the chamber retaining the sealing members 221). Also, the seal member H6 provides means whereby oil in the chamber 1, when drained therefrom, can be lifted to a considerable heighth so as to return the oil to an overhead reservoir on the hydraulic press, any pressure of the oil in the passage I20, and thus the chamber III, as a result of the head of oil from the overhead reservoir will result in apply- 10 ing sufficient pressure upon the seal member H8 to cause the same to apply suflicient pressure upon the surface of the ram lllb to prevent leakage of oil between the ram and the seal member and lift the oil to the overhead reservoir.

While the structural arrangement of the ap- Daratus disclosed and described herein constitutes preferred forms of the invention, it is to be understood that the apparatus is capable of structural illustration without departing from .the spirit of the invention, and that all modifications that fall within the scope of the appended claims are intended to be included herein.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In combination, a hydraulic cylinder, a ram reciprocable in said cylinder and extending from one endthereof, and a seal around said ram that includes, a packing member disposed between said ram and said cylinder, a retaining ring for retaining said packing member in position between said ram and said cylinder and for applying pressure thereupon to produce frictional engagement between said ram and said cylinder to such an extent that a determined and controlled flow of hydraulic fluid will pass between said ram and said packing member, a recess in said retaining ring containing a seal member contacting the wall of said cylinder to prevent fluid from passing along the cylinder wall beyond said sealing member, a wiping means frictionally engaging said ram and positioned for wiping the fluid from the surface of said ram after the fluid has passed between said packing member and the ram and for directing the fluid from the surface of the ram into a collecting chamber, a fluid collecting chamber positioned between said wiping means and said packing member to collect fluid passing between said packing member and said ram and which is directed thereinto by said wiping means, means for conducting fluid collected in said chamber away from the same, and a passage connecting said recess with said collecting chamber to relieve fluid pressure from said recess.

2. In combination a hydraulic cylinder, a ram reciprocable in said cylinder and extending from one end thereof, and aseal around said ram that includes, a packing member disposed between said ram and said cylinder, a retaining ring for retaining said packing member in position between said ram and said cylinder and for applying pressure thereupon to produce frictional engagement between said ram and said cylinder to such an extent that a determined and controlled flow of hydraulic fluid will pass between said ram and said packing member, a resilient wiping means having a plurality of annularly disposed recesses therein on both sides of the annular center line of said wiping means which provide ledge segments and which are disposed in oppositely directed positions on opposite sides of the annular center line of said wiping means to thereby be positioned against the direction of movement of the ram when reciprocating in the cylinder and for frictionally applying pressure upon the surface of said ram, said wiping means being positioned for wiping the fluid from the surface of said ram after the fluid has passed between said packing member and the ram and for directing the fluid from the surface of the ram into a collecting chamber, a fluid collecting chamber positioned between said wiping means and said packing member to collect fluid passing between said packing member and said ram and which is directed thereinto by said wiping means, means for conducting fluid collected in said chamber away from said ram, and a resilient seal member positioned adjacent said wiping means and between the wiping means and said packing member and frictionally applying pressure upon the wall of said cylinder to prevent fluid from passing along the cylinder wail beyond said sealing member,

- O I'IO M. SUMMERS.

REFERENCES CITED The following references are of record in the file of this patent:

Number 1 Number 12 UNITED STATES PATENTS Name Date Ellis Jan. 31, 1871 Graves Nov. 6, 1888 Pollitz Jan. 1, 1935 Oberstadt Dec. 5, 1939 Osmun Sept. 15, 1942 FOREIGN PATENTS Country Date Great Britain Mar. 17, 1910 Great Britain 1907